1. Field of the Invention
The present invention relates to polyvinyl chloride compositions. The present invention particularly relates to flexible polyvinyl chloride compositions exhibiting high thermal stability.
2. Description of the Prior Art
Chlorine containing polymers in general and polyvinyl chloride (PVC) compositions in specific are well known materials having a wide variety of commercial uses. As are most polymers, chlorine containing polymers can be subject to thermal and oxidative decomposition. U.S. Pat. No. 6,096,820 to Lockledge, et al., describes using a synthetic crystalline aluminosilicate to impart thermal stability to PVC. Materials such as the aluminosilicates can impart properties to polymers which are not always desirable.
Other materials are known in the art to act as stabilizers. For example, the patents DE 1694873, U.S. Pat. Nos. 4,656,209, 5,925,696, GB (A) 2,318,188A, EP (A1) 967 209, EP (A1) 967 245, and EP (A1) 967208 describe using monomeric aminouracyls and aminothiouracyls as PVC stabilizers.
It would be desirable in the art of preparing chlorine containing polymers to prepare such polymers with stabilizers which allow for the preparation of a fully transparent stabilized system which can be processed at high temperatures for long periods without staining or blistering. It would also be desirable in the art to prepare such polymers where the polymer is PVC. It would be even more desirable in the art if the PVC were a flexible PVC.
In one aspect, the present invention is a chlorine-containing polymer composition exhibiting high thermal and oxidative stability comprising a chlorine-containing polymer and a stabilizer selected from the group consisting of oligomeric aminouracyls, polymeric aminouracyls and mixtures thereof.
In another aspect, the present invention is a stabilizer composition suitable for the stabilization of chlorine containing polymers comprising an oligomeric and/or polymeric aminouracyl compound having a structure of: (a) repeating units of general formula (I): 
wherein:
R is selected from the group consisting of H; a C1-C18 linear or branched alkyl; a C5-C8 cycloalkyl; an aryl; an aryl substituted with xe2x80x94OH or C1-C8 alkoxy (here and hereafter called xe2x80x9csubstituted arylxe2x80x9d); an arylalkyl; an alkylaryl; and mixtures thereof;
R1 is selected from the group consisting of H; a xe2x80x94(Cxe2x95x90O)xe2x80x94C1-C12 linear or branched alkyl; a xe2x80x94(Cxe2x95x90O)xe2x80x94Oxe2x80x94C1-C12 linear or branched alkyl; a xe2x80x94(Cxe2x95x90O) phenyl, wherein the phenyl is unsubstituted or substituted with xe2x80x94OH; a C1-C8 linear or branched alkyl; a C1-C8 alkoxy;
and mixtures thereof; and
Z is O or S;
(b) linking groups between the repetitive groups of formula (I) which are the same or different and are selected from the group consisting of: (CR2R3)nxe2x80x94, wherein n is an integer having a value of from 2 to 12 and R2 and R3 can be the same or different and each independently of the other is selected from the group consisting of H, a C1-C12 linear, branched or cyclic alkyl, and mixtures thereof; 3-methylene-3,5,5-trimethylcyclohexan-1-yl; methylenebis(4-cyclohexyl); methylenebis(3-cyclohexyl); 1,4-phenylene; 1-methyl-2,4-phenylene; 4,4xe2x80x2-diphenylenemethane; and mixtures thereof;
(c) terminal groups selected from the group consisting of: H; a C1-C18 linear or branched alkyl; a C5-C8 cycloalkyl; a C3-C18 alkenyl; an aryl; a substituted aryl; an arylalkyl; an alkylaryl; a C1-C18 hydroxyalkyl; a C2-C18 alkoxy alkyl; a C6-C10 cycloalkoxyalkyl; a C7-C14 alkoxyaryl; a C7-C14 aryloxyalkyl; a C2-C8 alkylthioalkyl; a C6-C10 cycloalkylthioalkyl; a C7-C14 arylthioalkyl; a C7-C14 arylthioalkyl; a C1-C18 alkylamine, disubstituted with a C1-C18 linear or branched alkyl; and mixtures thereof.
According to the present invention, flexible PVC compositions with high thermal stability can be prepared using oligomeric and/or polymeric aminouracyls as stabilizers. These stabilizers are compounds having a structure of: (a) repeating units of general formula (I): 
wherein:
R is selected from the group consisting of H; a C1-C18 linear or branched alkyl; a C5-C8 cycloalkyl; an aryl; a substituted aryl; an arylalkyl; an alkylaryl; and mixtures thereof,
R1 is selected from the group consisting of H; a xe2x80x94(Cxe2x95x90O)xe2x80x94C1-C12 linear or branched alkyl;
a xe2x80x94(Cxe2x95x90O)xe2x80x94Oxe2x80x94C1-C12 linear or branched alkyl; a xe2x80x94(Cxe2x95x90O) phenyl, wherein the phenyl is unsubstituted or substituted with xe2x80x94OH; a C1-C8 linear or branched alkyl; a C1-C8 alkoxy;
and mixtures thereof; and
Z is O or S;
(b) linking groups between the repetitive groups of formula (I) which are the same or different and are selected from the group consisting of: xe2x80x94(CR2R3)nxe2x80x94, wherein n is an integer having a value of from 2 to 12 and R2 and R3 can be the same or different and each independently of the other is selected from the group consisting of H, a C1-C12 linear, branched or cyclic alkyl; and mixtures thereof; 3-methylene-3,5,5-trimethylcyclohexan-1-yl; methylenebis(4-cyclohexyl); methylenebis(3-cyclohexyl); 1,4-phenylene; 1-methyl-2,4-phenylene; and 4,4xe2x80x2-diphenylenemethane;
(c) terminal groups selected from the group consisting of: H; a C1-C18 linear or branched alkyl; a C5-C8 cycloalkyl; a C3-C18 alkenyl; an aryl; a substituted aryl; an arylalkyl; an alkylaryl; a C1-C18 hydroxyalkyl; a C2-C18 alkoxy alkyl; a C6-C10cycloalkoxyalkyl; a C7-C14 alkoxyaryl; a C7-C14 aryloxyalkyl; a C2-C8 alkylthioalkyl; a C6-C10 cycloalkylthioalkyl; a C7-C14 alkylthioaryl; a C7-C14 arylthioalkyl; a C1-C18 alkylamine, disubstituted with a C1-C18 linear or branched alkyl; and mixtures thereof.
Preferably, in general formula I, R is selected from the group consisting of: H, a C1-C18 linear or branched alkyl, a C5-C8 cycloalkyl, an aryl, an aryl substituted with xe2x80x94OH or C1-C8 alkoxy, and mixtures thereof; R1 is H; and the terminal groups are selected from the group consisting of: H; a C1-C18 linear or branched alkyl; a C5-C8 cycloalkyl; a C3-C18 alkenyl; an aryl; an aryl substituted with xe2x80x94OH or C1-C8 alkoxy; a C1-C18 alkylamine, disubstituted with C1-C18 linear or branched alkyl; and mixtures thereof.
Oligomeric and/or polymeric aminouracyls according to the present invention have a mean molecular weight of from 280 and 5,000.
Oligomeric and/or polymeric aminouracyls according to the present invention are normally obtained by cyclization of an oligomeric and/or polymeric urea using cyanacetic acid or its derivatives. The product thus obtained can be further derivatized to give compounds where R and R1 are different from H.
Preferably, the cyclization is carried out on a polyurea prepared by oligomerization and/or polymerization using suitable combinations of:
(A) a diisocyanate (DD) of formula OCNxe2x80x94Yxe2x80x94NCO wherein Y is selected from the group consisting of: xe2x80x94(CR2R3)nxe2x80x94, wherein n is an integer having a value of from 2 to 12 and R2 and R3 are the same or different and each independently of the other is selected from the group consisting of H, a C1-C12 linear or branched or cyclic, and mixtures thereof; 3-methylene-3,5,5-trimethylcyclohexan-1-yl; methylenebis(4-cyclohexyl); methylenebis(3-cyclohexyl); 1,4-phenylene; 1-methyl-2,4-phenylene; 4,4xe2x80x2-diphenylenemethane; and mixtures thereof;
(B) an amine (A) of the general formula Xxe2x80x94NH2 wherein X is selected from the group consisting of: H; a C1-C18 linear or branched alkyl; a C5-C8 cycloalkyl; C3-Cxcx9calkenyl; an aryl; a substituted aryl; an arylalkyl; an alkylaryl; a C1-C18 hydroxyalkyl; a C2-C18 alkoxy alkyl; a C6-C10 cycloalkoxyalkyl; a C7-C14 alkoxyaryl; a C7-C14 aryloxyalkyl; a C2-C8 alkylthioalkyl; a C6-C10 cycloalkylthioalkyl; a C7-C14 alkylthioaryl; a C7-C14 arylthioalkyl; a C1-C18 alkylamine, disubstituted with C1-C18 linear or branched alkyl; and mixtures thereof;
(C) a diamine (AA) of the general formula H2Nxe2x80x94Kxe2x80x94NH2 wherein K is selected from the group consisting of:xe2x80x94(CR2R3)nxe2x80x94, wherein n is an integer having a value of 2 to 12 and R2 and R3 are the same or different and each independently of the other is selected from the group consisting of H, a C1-C12 linear or branched or cyclic alkyl, and mixtures thereof; 3-methylene-3,5,5-trimethylcyclohexan-1-yl; methylenebis(4-cyclohexyl); methylenebis(3-cyclohexyl); 1,4-phenylene; 1-methyl-2,4-phenylene; 4,4xe2x80x2-diphenylenemethane and mixture thereof; and
(D) an isocyanate of formula Wxe2x80x94NCO (D), where W is selected from the group consisting of: a C1-C18 linear or branched alkyl; a C5-C8 cycloalkyl; a C3-C18 alkenyl; an aryl; a substituted aryl; an arylalkyl; an alkylaryl; a C1-C18 hydroxyalkyl; a C2-C18 alkoxy alkyl; a C6-C10 cycloalkoxyalkyl; a C7-C14 alkoxyaryl; a C7-C14 aryloxyalkyl; a C2-C8 alkylthioalkyl; a C6-C10 cycloalkylthioalkyl; a C7-C14 alkylthioaryl; a C7-C14 arylthioalkyl; a C1-C18 alkylamine, disubstituted with C1-C18 linear or branched alkyl; and mixtures thereof.
According to the present invention in the preparation of the polyurea A, AA, D, DD can be used in all possible ratios. In the preferred embodiments, when AA and D are both equal to zero, the molar ratio DD/A is comprised between 0.3 and 0.6; when DD and A are both equal to zero, the molar ratio AA/D is comprised between 0.3 and 0.6. Obviously, the above description which was done assuming that Z is O in the repetitive group of formula (I) can be similarly repeated when Z is S by using the corresponding sulphurated compounds; in this case D and DD mean the corresponding isothiocyanate and diisothiocyanate.
According to the present invention, in flexible PVC compositions with a high thermal stability, the oligomeric and/or polymeric aminouracyl stabilizers may be incorporated in an amount of from 0.01 to 10% by weight, preferably of from 0.05 to 5% and most preferably of from 0.1 to 3% based on the entire composition.
According to the present invention, stabilized PVC compositions can further contain customary additives such as, but not exclusively: stabilizers, auxiliaries and processing aids, compounds containing alkali metal compounds and alkaline earth metal compounds, lubricants, plasticizers, pigments, fillers, phosphites, thiophosphites, thiophosphates, mercaptocarboxylates, epoxidized fatty acid esters, antioxidants, UV absorbers and light stabilizers, fluorescent whitening agents, impact modifiers, gelling agents and antistatic agents, metals deactivators, flame retardants, blowing agents and antifogging agents.
Examples of plasticizers that can be used according to the present invention are: esters of C4-C20 alcohols such as adipates, phthalates, trimellitates, azelates, sebacates, benzoates, phosphates; epoxidized compounds, typically epoxidized soy-bean oil; polymeric plasticizers such as polyester, polyadipates, polyphosphates, and the like.
The compounds of the present invention are useful as stabilizers for chlorine containing polymers such as polymers of vinyl chloride, vinyl resins containing vinyl chloride units in the structure, such as copolymers of vinyl chloride and vinyl esters of aliphatic acids, preferably vinyl acetate, copolymers of vinyl chloride with esters of acrylic and methacrylic acid and with acrylonitrile, copolymers of vinyl chloride with diene compounds and unsaturated dicarboxylic acids or their anhydrides, such as copolymers of vinyl chloride with diethyl maleate, diethyl fumarate or maleic acid anhydride, post-chlorinated polymers and copolymers of vinyl chloride and vinyliden chloride with unsaturated aldehydes and ketones, such as acrolein, crotonaldehyde, vinyl methyl ketone, vinylmethylether, vinyl isobutylether and the like; polymers of vinylidene chloride and copolymers thereof with vinyl chlorides or other polymerizable compounds; polymers of vinyl chloroacetate and dichlorovinyl ether; chlorinated polymers of vinyl acetate, chlorinated polymeric esters of acrylic acid and of xcex1-substituted acrylic acid; polymers of chlorinated styrene; chlorinated rubbers; chlorinated polymers of ethylene; polymers and post-chlorinated polymers of chlorobutadiene and their copolymers with vinyl chloride, chlorinated rubber; mixtures of the cited polymers alone or with other polymerizable compounds. Included in these materials are also graft polymers of PVC with EVA, ABS and MBS. Preferred substrates are also mixtures of above homo and copolymers, preferably homopolymers of vinyl chloride with other thermoplastic or elastomeric polymers, in particular blends with ABS, MBS, NBR, SAN, EVA, CPE, MBAS, PMA, PMMA, EPDM and polylactones.
Suitable compositions for use with the stabilizers of the present invention are preferably recycled chlorine containing polymers. These polymers are the above mentioned polymers which have suffered damage through use, storage or production process. Particularly preferred is recycled PVC. Recycled products may also contain minor amounts of foreign material difficult to remove, such as paper, pigments, adhesives.
The compositions of PVC containing the stabilizers of the present invention, show as their fundamental characteristic a high thermal stability together with a good transparency of the stabilized system, without staining and blistering. These properties of the compositions of PVC according to the invention, are very different from those described in the known art. This is demonstrated by the applicative results obtained on compositions of PVC containing the oligomeric and/or polymeric aminouracyls of the present invention.